This invention relates generally to a lockset mechanism for a door assembly, and more specifically to a means and method for establishing a semi-permanent mechanical connection between the interior and exterior cylinder assemblies of a lockset mechanism.
In conventional locksets, the interconnection between the interior and exterior rose assemblies is established by the use of threaded fasteners. The exterior rose assembly typically includes two internally threaded bosses which align with two apertures formed on the interior rose assembly. Standard machine screws are inserted into the interior rose apertures and are brought into alignment with and threadingly engage the threaded bosses formed on the exterior rose assembly. Tightening the screws closes the interior and exterior roses toward each other, thereby trapping the door therebetween. A typical lockset of the type described above is illustrated in FIG. 1.
There are numerous disadvantages to this conventional method of establishing a semi-permanent mechanical connection between the interior and exterior rose assemblies of the lockset. In particular the access to the screw heads may be partially concealed behind the door knob making manipulation awkward. In addition, the screws typically used for this purpose are relatively long (often 1 inch or more in total length) to permit a single lockset to accommodate doors of varying thicknesses, typically in the range of 1xe2x85x9c to 1xc2xe inch door thicknesses. The length of the screws requires that the screws be turned many times when the lockset is being installed on thinner doors, thereby reducing the speed of installation. Furthermore, the bosses must be internally threaded deeply enough to accommodate the length of the screws when the lockset mechanism is installed on thinner doors. Such deep internally threaded features are difficult to produce in high volume and add to the cost of manufacture.
The use of conventional machine screws in the installation of the lockset requires that the installer have an appropriate tools available, to drive the screws. The use of such tools in connection with the awkward access to the screw heads due to concealment by the door knob creates significant risk of cosmetic damage to the interior rose should the tool slip off the screw head. If such damage occurs, the installer may be required to remove and replace the interior rose and knob assembly, particularly in new construction applications. Moreover, the risk of cosmetic damage also discourages the use of power drivers, thereby further reducing the speed of installation.
In some lockset applications, particularly locksets with lever handles, it is desirable to have a torque spring associated with each of the interior and exterior knob/handle and rose assemblies which operate independently on the respective knob or handle. The use of two torque springs provides redundancy in the lockset, and also prevents sagging which may occur when handles are left unsprung. A previously unrecognized problem with the use of dual independent torque springs is that the interconnection of the spring between the rose and knob assemblies prevents the free rotation of the rose with respect to the knob or handle. In conjunction with the present invention, this problem prevents the use of dual independent torque springs on a lockset mechanism having a means for quick and tool-free installation thereof.
Therefore, it is an object of the present invention to provide a means and method of establishing a semi-permanent mechanical connection between the interior and exterior rose assemblies of a lockset which does not require the use of machine screws or similar threaded fasteners, but which can still accommodate doors of varying thicknesses, particularly in the range of 1xe2x85x9c inch to 1xc2xe inch.
It is another object of the present invention to provide a means and method of establishing a semi-permanent connection between the interior and exterior rose assemblies of a lockset which does not require the use of tools for installation, while still permitting easy un-installation and reuse with a minimum of tools.
It is a further object of the present invention to provide a means and method of establishing a semi-permanent mechanical connection between the interior and exterior rose assemblies of a lockset which permits very rapid installation.
It is an additional object of the present invention to provide dual independent torque springs in connection with such a quick install lockset mechanism.
It is yet another object of the present invention to provide a lockset mechanism having features for facilitating proper alignment of the interior and exterior rose assemblies during installation.
It is still a further object of the present invention to provide a lockset mechanism having a turnpiece guide for facilitating proper alignment of the lock mechanism during installation.